Minimally invasive surgical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. As a consequence, the average length of a hospital stay for standard surgery may be shortened significantly using minimally invasive surgical techniques. Also, patient recovery time, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.
A common form of minimally invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient's abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately ½ inch or less) incisions to provide entry ports for laparoscopic instruments. Laparoscopic surgical instruments generally include a laparoscope or an endoscope for viewing the surgical field.
An endoscope can be calibrated prior to use. In general, calibration is beneficial for many advanced imaging systems, such as advanced computer vision, three-dimensional augmented reality, three-dimensional visualization applications, advanced user interfaces, and image-guided surgery. Such calibration often makes use of a pattern of features that can be imaged by the endoscope to provide calibration data.
Existing calibration devices and methods suffer from a number of problems. For example, properly positioning and orienting the calibration pattern of image features of some prior art calibration targets relative to the imaging device may not be intuitive, and it may therefore be difficult for non-technical persons to obtain the desired calibration. Additionally, since human hands are not very steady, holding the camera or target freehand typically induces motion blur, while having to resort to a large, benchtop endoscopic support might render the system too unwieldy for regular use in the field. Some methods also require manually designating characteristics of the pattern in the resulting images, which may also lead to errors in calibration.
An endoscopic imaging system may also have its color balance (such as white balance) adjusted. In image processing, color balance involves the adjustment of the intensities of colors, typically the red, green and blue primary colors. A goal of this adjustment is to render specific colors correctly, particularly neutral colors. It may also be advantageous to subject an endoscopic-imaging system to diagnostic testing from time to time. A typical endoscopic imaging system includes a variety of components, such as imaging sensors, lens assemblies, etc., that may functionally degrade or fail over time. Where functional degradation that does not rise to an intolerable level has occurred, an endoscopic imaging system may continue to be used due to a lack of knowledge on the part of the user that any functional degradation has occurred. Such latent functional degradation may have significant detrimental consequences in a critical image-guided procedure, such as many minimally invasive surgeries.
While imaging-device calibration, alignment, color balance, and diagnostic testing may be performed by using existing methods and devices, improved methods, devices, and assemblies for performing these tasks in a more convenient and efficient manner remain of interest. For example, methods and assemblies that can be conveniently used to perform some or all of these tasks in a time- and space-efficient manner prior to a surgery, without having to resort to excessive additional training of surgical staff, would be of particular interest.